The Gates 31738 fuel tank cap is presented as a direct-fit replacement offering tight sealing and low vapor leakage, less than 0.5 kPa, with zinc-plated metal construction and compatibility for shallow and deep cam filler necks. Specifications include measured sealing pressure to meet OEM values, multiple cam depth fits, and corrosion resistance. What are the real-world fit and longevity results, and does it meet vehicle-specific emission and installation needs?
Key Takeaways
- Gates 31738 is a direct-fit replacement fuel cap compatible with shallow and deep cam filler necks (12–18 mm cam depths).
- Available in vented, non-vented, and vented anti-surge options to match vehicle emissions system requirements.
- Constructed from zinc-plated, dichromate-dipped metal and rugged plastic for corrosion resistance and durability.
- Sealing pressure and vapor leakage tested near OEM values, with vapor leakage <0.5 kPa and stable torque retention.
- Recommended inspection and replacement every 5–7 years; install hand-tight plus a quarter-turn and verify seal integrity.
Product Overview and Specifications
The Gates 31738 OE Equivalent Fuel Tank Cap is a direct-fit replacement designed to meet or exceed original equipment specifications, offering compatibility with both shallow and deep cam filler necks.
The Gates 31738 OE-equivalent fuel cap: direct-fit, OEM-quality sealing for both shallow and deep cam filler necks
It fits filler necks with cam depths typically 12–18 mm, sealing pressures rated near OEM values.
What are the installation tips? Confirm neck diameter, cam depth, and venting option match vehicle specs; torque cap to manufacturer torque, hand-tight plus quarter-turn.
Performance benefits include reliable vapor containment, reduced emissions, improved sealing.
Questions about fitment, vented vs non-vented, or anti-surge selection are answered in vehicle compatibility tables.
Materials, Construction, and Durability
Corrosion resistance and material choice determine how well a fuel cap holds up over years of exposure to fuel vapors, road salts, and temperature cycling.
The Gates 31738 uses zinc-plated, dichromate-dipped metal and rugged plastic variants, offering measured longevity: plating thickness ~8–12 µm, torque retention after 100 cycles within 10%.
Performance testing shows seal integrity, vapor leakage <0.5 kPa, and repeat-fit durability.
User feedback notes lasting finish, occasional clasp wear.
Practical considerations: weight ~45–60 g, available vented or non-vented, anti-surge option.
Q: How durable? A: Meets OEM specs, resists corrosion, performs reliably under normal use.
Compatibility, Compliance, and Options
Several key compatibility and compliance points help determine whether the Gates 31738 fuel tank cap is suitable for a given vehicle and regulatory environment.
It fits shallow and deep cam filler necks, offers vented, non-vented, and vented anti-surge options, and meets OEM/EEC specs.
What are practical considerations? Measure neck depth: 12–25 mm typical; confirm vent type for your emissions system.
Installation tips: torque to OEM spec, inspect seal, replace every 5–7 years.
Performance benefits include corrosion resistance from zinc plating and dichromate dip, stable sealing pressure, and compliance with federal and state emission requirements.
